Who knew that looking into the evolution of bipedalism (walking on two feet) had such implications for our health, and the way we run today.
I think the editor's summary is better than anything I could come up with, so I'll share it with you here:
"Before the introduction of modern padded running shoes in the 1970s, and for most of human evolutionary history, humans ran either barefoot or in minimal shoes. A comparison by Daniel Lieberman and colleagues of the biomechanics of habitually shod versus habitually barefoot runners now suggests that the collision-free way that barefoot runners typically land is not only comfortable but may also help avoid some impact-related repetitive stress injuries. Kinematic and kinetic analyses show that modern shoes allow runners to land on the heel, as they do when they walk. Runners who don't wear shoes land more often on the ball of the foot or with a flat foot. This means that they often flex their ankles as they strike the ground and generate smaller impact forces than shod, rear-foot, strikers — compare the impact generated by landing from a jump on your heel versus your toes."
You can find the summary, original research, and letter here.